The sia Group, with its headquarters in Frauenfeld, Switzerland, is one of the worlds three leading suppliers of innovative abrasive systems. It develops, manufactures and markets complete abrasive systems, tailored to ......The sia Group, with its headquarters in Frauenfeld, Switzerland, is one of the worlds three leading suppliers of innovative abrasive systems. It develops, manufactures and markets complete abrasive systems, tailored to specific requirements and applications, for the surface treatment of every type of workpiece. These products turn sanding and grinding into surface technology. sia Abrasives employs approximately 1250 personnel worldwide and is represented with partners in over 80 countries.